Emergency brake for elevator cars



Aug. 4, 1959 H. E. FALTER ET AL EMERGENCY BRAKE FOR ELEVATOR CARS FiledJan. 28, 19 58 5 Sheets-Sheet 1 FIG. 2

INVENTORS ROBERT A. VAUGHAN HENRY E. F'ALTER CORBETT, MAHO EY, MILLER &RAMBO W ATTORNEYS 1959 H. E. FALTER ET AL 2,897,920

EMERGENCY BRAKE FOR ELEVATOR CARS Filed Jan. 28, 1958 s Sheets-Sheet 243a 42av 42 "'II' MHVWW 25 "n /4|a FIG 8 soggy INVENTORS 4IC ROBERT A.VAUGHAN HENRY E. FALTER BY CORBETT, MAHONE MILLER & RAMBO BY i ATTORNEYSAug. 4, 1959 Filed Jan. 28, 1958 H. E. FALTER ETAL- 2,897,920

EMERGENCY BRAKE FOR ELEVATOR CARS 3 Sheets-Sheet 3 4: niiliii 7INVENTORS ROBERT A. VAUGHAN HENRY E. FALTER BY CORBETT, MAHONEY, MILLER8. RAMBO BY ,d ATTORNEYS United States Patent 2,897,920 EMERGENCY BRAKEFOR ELEVATOR CARS Henry E. Falter and Robert A. Vaughan, Columbus,

Ohio, assignors, by mesne assignments, to Dresser Industries, Inc.,Dallas, Tex., a corporation of Delaware Application January 28, 1958,Serial No. 711,692

8 Claims. (Cl. 187-88) This invention relates to an emergency brake forelevator cars. It has to do, more particularly, with an emergency brakefor use on elevator cars of the one or two-man type commonly used inconnection with antenna or similar towers.

It has been common to provide small elevators or lifts in connectionwith towers of this type so as to provide speedy means for access to thetop of the tower for servicing the antenna or other equipment at thetop. These elevators are usually guided by vertically extending guiderails secured to the tower framework and with which guide rollers,carried by the car, cooperate. The elevator is suspended in the tower bymeans of hoist mechanism including a lift cable. Obviously, it would bedesirable to provide a safety brake for preventing dropping of the carin case the cable breaks or the lifting force thereon is eliminated bysome breakdown in the hoist mechanism.

It is the main object of this invention to provide a simple andeffective emergency brake associated with the guide structure of anelevator car of the type indicated which will prevent dropping of thecar in case of failure of the lift cable or mechanism.

Another object of this invention is to provide an emergency brake willoperate automatically to prevent dropping of the car if the liftingforce is released from the car but which can also be operated manuallyfrom within the car if desirable or necessary.

Another object of this invention is to provide an emergency brake whichis so designed that maximum braking effect will be obtained.

A further object of this invention is to provide an emergency brake ofthe type indicated which can be,

released from inside the car afiter operation.

Various other objects will be apparent.

In the accompanying drawings, one embodiment of this invention isillustrated but it is to be understood that specific details thereof maybe varied without departing from the basic principles of this invention.

In the drawings:

Figure 1 is a side elevational view illustrating a tower structurehaving an elevator mounted thereon with the emergency brake of thisinvention associated therewith.

Figure 2 is a horizontal sectional view taken along line 2-2 of Figure1.

Figure 3 is an enlarged side elevational view of the elevator carshowing the emergency brake associated therewith.

Figure 4 is a vertical sectional view taken along line 4-4 of Figure 3.

Figure 5 is a vertical sectional view taken along line 5-5 of Figure 4.

Figure 6 is a vertical sectional view taken along line 6-6 of Figure 4.

Figure 7 is a horizontal sectional view taken along line 7-7 of Figure 5showing the brake released.

r 2,897,920 Patented Aug. 4, 1959 ICC Figure 8 is a view similar toFigure 7 but showing the brake applied.

Figure 9 is an enlarged detail in vertical section showing the brakeroller and associated parts.

Figure 10 is an isometric view showing the brake roller and associatedparts.

Figure 11 is a horizontal sectional View taken along line 11-11 ofFigure 3.

Figure 12, is a horizontal sectional view taken along line 12-12 ofFigure 5 showing the brake applied.

Figure 13 is a view similar to Figure 12 but showing how the brake canbe released from within the car.

Figure 14 is a sectional view taken along line 14-14 of Figure 12.

With reference to the drawings, in Figure 1 there is illustrated a towerof the open framework type which includes the vertically extendingsupporting rails or posts 10 and the horizontally extending bars orbraces 11 which are suitably secured to the rails 10. As indicated inFigure 2, the tower is of triangular form in horizontal section. Thetower is supported on a base 12 and is held upright by the guy-wires 13.It is to be understood, however, that this invention is applicable totowers of other types and that the one shown is for illustrativepurposes only.

At two sides of the tower, there are provided the elevator car guiderails 15 which are attached to the associated horizontally disposedsupports 11a that are secured to the cross members 11. The guide rails15 will usually extend the full height of the tower. Carried by thespaced parallel guide rails 15 is an elevator car 16 of a suitable typehaving a forward open side for access. The car carries upper and lowersets of rollers 17 and 18, respectively, at each side for cooperationwith the associated guide rail 15. The rollers and associated guiderails are preferably ofthe type disclosed in the :copending applicationof Robert A. Vaughan, directed to Elevator Car Guiding System, SerialNo. 711,- 303, filed January 28, 1958.

The elevator car 16 is raised and lowered by means of a cable sheavingsystem operated by means of a hoist unit 2%) provided on the base 12.This system includes the lift cable 21 attached to the top of the carand the cable tensioning system including the cable 22 attached to thebottom of the car and associated with counterbalance weights 23 mountedfor vertical movement at the lower end of the tower.

The present invention relates to an emergency brake mechanism 25associated with the car 16 adjacent the upper end thereof and adapted tocooperate with the guide rails 15.

The brake mechanism includes a brake unit disposed at each side of theelevator car 16. Each unit comprises a brake roller 26 and a spacedbrake shoe 27 which will be on opposite sides of the associated guiderail 15 :which is illustrated as being a cylindrical rod. The shoe 27 isfixed to the side 16a of the car and provides a vertically disposedflange 27a which faces towards the guide 15 to serve as an elongatedflat frictional surface for contact with the guide 15.

The brake roller 26 (Figure 10) is provided with a knurled frictionsurface for engaging the guide rail 15 at the side opposite the fixedshoe 27 and is carried by a transversely extending cam follower pin 28which projects in both directions into the cam slots 29 formed in thevertically disposed cam flanges 30 which are formed in spaced parallelrelationship on a supporting bracket 30a which is rigidly secured to theside Wall 16a of the elevator car on its outer side. Mounted on thebracket 30a at the level of the straight shoe 27 (Figure 5) and directlyopposite it is a wedge shoe 30b which has a.

roller engaging outer surface 300 that is inclined outwardly towards itsupper end. Thus, the shoe 3% is wedge-shaped in a vertical plane, asindicated by a comparison of Figures 7 and 12, but it is alsowedge-shaped in a horizontal plane, as shown by these figures. It willbe noted that the inner surface 30d of the shoe 30b is inclined so thatthe shoe is narrower towards its inner side and that the contactingsurface of the bracket 30a is reversely angled. The shoe 30b is providedwith a horizontal lug 30a, intermediate its height, which extends 10inwardly through an opening 16c in the wall 16a of the car 16. The wedgeshoe 30b is normally held with the lug 30e projecting into the car 16 bymeans of the bolts 30] which project through the wall 16a and whichcarry lock nuts 30g that can be loosened from within the car 16.

The brake roller 26 is disposed within the lower end of a yoke 31 whichis disposed between the cam flanges 30 and which is pivoted at its lowerend to the cam follower pin 28 and at its upper end to a second camfollower pin 32. This pin 32 also projects in both directions andoperates in the slots 29 of the flanges 30. Pivoted to the upper end ofthe yoke 31 at the pin 32 is the lower end of a link 33. This link ispivoted at its upper end by a pivot 34 to a toggle lever 35. The lever35 is pivoted intermediate its ends by a pivot 36 to an upstanding lug37 carried by the top wall 16b of the car 16. It will be noted that thepivot pin 34 is disposed at right angles to the pivot provided by thepin 32 and that the link 33 projects upwardly above the cam shoes 30with the pin 28 in the lowermost ends of the slots 29.

Normally, the brake roller 26 will be in the position shown in Figures 7and 10, where it will be swung away from the guide rail 15, due to thefact that each cam slot 29 is provided with the angled lower end portion29 which angles outwardly away from the guide rail 15 and is disposed inspaced parallel relationship to the angled surface 300 of the wedge shoe30b with which the roller engages. In this position of the roller, theroller itself and the stationary brake shoe 27 will be spaced from theguide rail 15 as shown best in Figure 7. However, if an upward pull isexerted by the link 33 on the roller-carrying yoke 31, the pin 28 willbe pulled upwardly in the angled portions 38 of the slots 29 and the pin32 will be pulled upwardly into the connecting straight upper portions39 of the slots 29. This will result in positively moving the roller 26along the inclined shoe surface 360 so as to wedge it into engagementwith the guide 15 to grip the guide between it and the associated fixedshoe 27, as shown in Figure 8. The slot portions 38 and the shoe surface30c will be of suflicient length and angled inwardly towards the axis ofthe rail 15 to provide sufiicient overrun to insure that the rail 15will be gripped between the brake roller 26 and the fixed brake shoe 27substantially before the pin 28 reaches the upper ends of the angledportions 38 of the slots and the roller 26 reaches the upper extent ofthe shoe surface 300. Thus, an override section of each cam slot andshoe surface is provided to insure adequate engagement of the roller 26with the guide 15. The upper straight 0 portion 39 of the slots providefor vertical travel of the link 33 and with the brake released, the pin32 is at the junction of the straight portions 39 with the angledportions 38 of the slots 29, as shown in Figure 10. The straight slotportions 39 are of sufiicient height that the pin 32 will never contactwith the upper ends thereof and, therefore, will not interfere with firmapplication of brake roller 26 to the guide rail 15.

The two levers 35 form part of a toggle mechanism for applying the brakeunits at each side of the car 16. It will be noted from Figures 4 and 6that the inner end of each of these levers 35 is pivoted at 40 to theouter end of a crosshead 41. This crosshead 41 is fixed to a dependingoperating rod 41a which is mounted for .slidable vertical movement in asleeve 41b secured in the top wall. The rod 41a extends down into theelevator car and is provided with a hand grip 41c. The inner ends of thelevers 35 are normally pulled upwardly by means of the tension springs42 which have their lower ends connected thereto and their upper endsconnected to angles 42a which are supported by the housing 16c mountedon the upper end of the car 16. These springs normally pull thecrosshead 41 upwardly into contact with the lower end of a rod 43 andkeep the rollers 26 in their lower or released positions.

The rod 43 is mounted for slidable vertical movement in a sleeve 43awhich is positioned on the top wall 16d of the housing 160. The upperend of this rod 43 is provided with a clevis connection 43b (Figure 6)for connecting the car to the suspending lift cable 21.

Upward movement of the rod 43 is resisted by means of a compressionspring 45 disposed between the lower end of the sleeve 43a and anadjustable stop angle bracket 46 which is associated with a nut 47threaded on the lower end of the rod 43. The upstanding flange of theangle 46 'will contact with a fixed stop member 50 to limit compressionof the spring 45. The spring 45 is compressed by the pull exerted by thelift cable 21 on the upper end of the rod 43 and, therefore, normallythe lift force will raise the lower end of the rod 43 to such an extentthat the inner ends of the toggle levers 35 will be swung upwardlysuificiently by the springs 42 so as to move their outer ends downwardlyand thereby move the brake rollers 26 away from the guide rails 15. Thebrake mechanism can be manually applied by means of the handle 410 onthe lower end of the rod 41a. Thus, a person in the car can apply thebrake units if sufficient pull is exerted on the handle 41c to overcomethe force exerted by the springs 42.

It will be apparent that during normal operation of the car 16 therewill be an upward pull exerted by the lift cable 21. This compresses thespring 45 and releases the brake rollers 26 (Figure 7) from theassociated guides 15. However, if the upward pull on the rod 42 isreleased by breaking of the cable 21 or for any other reason, thecompressed spring 45 will expand, thereby applying the brake units bypositively moving the rollers 26 into engagement with the rails 15(Figure 8) and gripping the rails between the rollers and the frictionsurfaces 27a of the fixed shoes 27. The weight of the car 16, and anypassenger carried thereby, will aid in the application of the brakes,since this weight will tend to move the pin 28 further upwardly andinwardly in the cam slots 29 and the roller 26 further upwardly alongshoe surface 30c thereby increasing the braking pressure exerted on theguide rail 15 by the roller 26 and the shoe 27. The expanding force ofthe spring 45 is greater than the combined tension forces exerted by thesprings 42 so that the force of the springs 42 will be readily overcometo apply the brake units. However, as the spring 45 is compressed, thesprings 42 will release the brake units. If it is desired to apply thebrake units manually while the cable 21 is still exerting its liftingaction, it is merely necessary to exert a downward pull on the handle410 to overcome the force of the springs 42. Thus, with this brakemechanism it will automatically function as a safety factor to preventdropping of the car 16 but the brake units can also be applied manuallyfrom within the car.

Another important feature of this invention is that the brake can bereleased, after once being applied, from inside the car. This can beaccomplished in the manner evident from a comparison of Figure 12 withFigure 13. The nuts 30g of each shoe 30b are retracted on the bolts 30ffrom within the car and the lug 30a is pounded outwardly. This will movethe shoe 3% bodily outwardly and, due to its wedge shape, will permitmovement of the roller 26 away from the guide 15. Thus, the rollers 26can be released from within the car to permit lowering of the car, afterthe lift force is restored, without climbing outside the car.

It will be apparent from the above that the brake unit comprises a firstspring unit for normally releasing the brake, as long as there is a liftforce applied to the car, and a second spring unit for applying thebrake whenever the lift force is not present. The first spring unit fornormally releasing the brake unit is controlled by the second springunit which is compressed by the lift force. This second spring unitnormally permits the first spring unit to release the brakes but whenthe lift force is eliminated and it expands, the second spring unitovercomes the first spring unit to apply the brake. When the lift forceis restored the brake can be released temporarily from within the car.

According to the provisions of the patent statutes, the principles ofthis invention have been explained and have been illustrated anddescribed in what is now considered to represent the best embodiment.However, it is to be understood that, within the scope of the appendedclaims, the invention may be practiced otherwise than as specificallyillustrated and described.

Having thus described this claimed is:

1. In combination with an elevator car movable vertically along a guiderail, a brake roller carried by the car for engaging the guide rail,means for moving the roller into engagement with the guide rail, saidmeans comprising a wedge shoe carried by the car on the exterior of oneof the vertical walls thereof, said shoe being mounted on a supportattached to the wall of the car, said shoe having an angled surfacecooperating with a reversely angled surface on said support, said angledsurfaces extending outwardly from said car, and means operable fromwithin the car for moving said shoe relative to said support.

2. In combination with an elevator car movable along a guide rail, liftmeans connected to said car, and an emergency brake unit operable whensaid lift means fails, said unit comprising a brake member movablycarried by the car adjacent the guide rail, first means for normallyholding said brake member away from said guide rail, second meansoperable by the lift means for controlling said first means to permit itto hold said brake member away from said guide rail as long as said liftmeans functions, and means operable from within the car for releasingthe brake member when it is once applied.

3. In combination with an elevator car movable along a guide rail, liftmeans connected to said car, and an emergency brake unit operable whensaid lift means fails, said brake unit comprising a brake roller movablymounted on the car and disposed on one side of the guide rail and abrake shoe mounted on' the car in fixed position and disposed on theopposite side of the guide rail, the brake roller and the brake shoecooperating to grip the guide rail therebetween when the lift force isreleased, an actuating lever connected to said brake roller, a firstspring unit acting on the lever for normally holding said brake rolleraway from said guide rail, a second spring unit for applying said brakeunit connected to said lift means so that it will be. inoperative untilthe lift means fails, said second spring unit opposing said first unitwhen said lift means fails to move said brake roller into contact withsaid guide rail and comprising a movable stop for engaging saidactuating lever to normally permit it to move to brake-releasingposition and a spring connected to said lift means for moving said stopmeans into brake-applying position when the lift means fails, a camstructure for positively moving the roller toward and away from theinvention, what is guide rail upon movement of the roller by saidactuating lever, comprising a roller-engaging wedge shoe opposite thefixed shoe and inclined inwardly and upwardly toward said fixed shoe,said wedge shoe being wedge-shaped in a. horizontal direction as well asa vertical direction, said wedge shoe having a releasing lug extendinginto the car, said wedge shoe having its smaller end inwardly andengaging a complemental angled supporting surface on. the car.

4. In combination with an elevator car movable along a guide rail, liftmeans connected to said car, and an emergency brake unit operable whensaid lift means fails, said brake unit comprising a brake roller movablymounted on the car and disposed on one side of the guide rail and abrake shoe mounted on the car in fixed position and disposed on theopposite side of the guide rail, the brake roller and the brake shoecooperating to grip the guide rail therebetween when the lift force isreleased, an actuating lever connected to said brake roller, a firstspring unit acting on the lever for normally holding said brake rolleraway from said guide rail, a second spring unit for applying said brakeunit connected to said lift means so that it will be inoperative untilthe lift means fails, said second spring unit opposing said first unitwhen said lift means fails to move said brake roller into contact withsaid guide rail and comprising a movable stop for engaging saidactuating lever to normally permit it to move to brake-releasingposition and a spring connected to said lift means for moving said stopmeans into brake-applying position when the lift means fails, a camstructure for positively moving the roller toward and away from theguide rail upon movement of the roller by said actuating levercomprising a roller-engaging wedge shoe opposite the fixed shoe andinclined inwardly and upwardly toward said fixed shoe, said wedge shoebeing mounted on the car for release from within the car.

5. The combination of claim 4 in which the second spring unit comprisesa compressible spring mounted on a lift rod forming a part of said liftmeans and compressible by the lift force applied to said rod butexpansible upon release thereof to move said roller so as to cause it topositively engage said guide rail.

6. The combination of claim 5 in which the car is guided by guide railson opposite sides thereof and brake units are provided at both sides ofthe car for cooperating with said guides, said lift rod being connectedto each of said brake units by said actuating lever, the two leversbeing mounted to provide toggle levers.

7. The combination of claim 6 in which the first unit includes springsconnected to the levers for releasing the brake units upon expanding ofsaid compressible spring.

8. The combination of claim 4 in which each brake roller is carried by apin operating in cam slots formed in said cam structure, said cam slotsand said wedge brake shoe being angled relative to the associated guiderail so that the weight of the car will move the brake roller intoengagement with said guide rail, said roller being connected to saidbrake actuating lever for movement thereby to move said pin in said camslots and move the roller along said wedge brake shoe.

References Cited in the file of this patent UNITED STATES PATENTS324,494 See Aug. 18, 1885 741,481 Fulwider Oct. 13, 1903 917,332 MalstonApr. 6, 1909 946,284 Stamp Jan. 11, 1910 1,707,099 Stein Mar. 26, 1929

